In Exercises 10.9.14, hypothesis tests are proposed. For each hypothesis test, do the following. Identify the variable. Identify the two populations. Determine the null and alternative hypotheses. Classify the hypothesis test as two tailed, left tailed, or right tailed. Spending at the Mall. An issue of USA TODAY discussed the amounts spent by teens and adults at shopping malls. Suppose that we want to perform a hypothesis test to decide whether the mean amount spent by teens is less than the mean amount spent by adults. A variable of two populations has a mean of 7.9 and a standard deviation of 5.4 for one of the populations and a mean of 7.1 and a standard deviation of 4.6 for the other population. For independent samples of sizes 3 and 6, respectively, find the mean and standard deviation of X1 - x2. Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer. Can you conclude that the variable X1 - x2 is normally distributed? Explain your answer.
Explanation / Answer
10.10a) Identity the variables. Outcome variable: spending amount at shopping malls Independent variable: Teen/Adult status